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3941. Metal-rich SX Phe stars in Kepler field
ID:
ivo://CDS.VizieR/J/MNRAS/466/1290
Title:
Metal-rich SX Phe stars in Kepler field
Short Name:
J/MNRAS/466/1290
Date:
21 Oct 2021
Publisher:
CDS
Description:
A spectroscopic and photometric analysis has been carried out for 32 candidate SX Phe variable blue straggler stars in the Kepler field. Radial velocities (RVs), space motions (U, V, W), projected rotation velocities (vsini), spectral types and atmospheric characteristics (T_eff_, logg, [Fe/H], {xi}_t_, {zeta}_RT_, etc.) are presented for 30 of the 32 stars. Although several stars are metal-weak with extreme halo orbits, the mean [Fe/H] of the sample is near-solar, thus the stars are more metal-rich than expected for a typical sample of Pop. II stars and more like halo metal-rich A-type stars. Two-thirds of the stars are fast rotators with vsini>50km/s^, including four stars with vsini>200km/s. Three of the stars have (negative) RVs>250km/s^, five have retrograde space motions and 21 have total speeds (relative to the Local Standard of Rest) >400km/s. All but one of the 30 stars have positions in a Toomre diagram consistent with the kinematics of bona fide halo stars (the exception being a thick-disc star). Observed Romer time delays, pulsation frequency modulations and light curves suggest that at least one-third of the stars are in binary (or triple) systems with orbital periods ranging from 2.3d to more than four years.
3942. M31F eclipsing binaries and Cepheids
ID:
ivo://CDS.VizieR/J/AJ/118/2211
Title:
M31F eclipsing binaries and Cepheids
Short Name:
J/AJ/118/2211
Date:
21 Oct 2021
Publisher:
CDS
Description:
As a first step in the DIRECT project, between September 1996 and October 1997 we obtained 95 full/partial nights on the F.L. Whipple Observatory 1.2m telescope and 36 full nights on the Michigan-Dartmouth-MIT 1.3 m telescope to search for DEBs and new Cepheids in the M31 and M33 galaxies. In this paper, the fifth in the series, we present the catalog of variable stars found in the field M31F [(RA, DE) = (10.10{deg}, 40.72{deg}), J2000.0]. We have found 64 variable stars: four eclipsing binaries, 52 Cepheids and eight other periodic, possible long-period or nonperiodic variables. The catalog of variables, as well as their photometry and finding charts, is available via anonymous ftp and the World Wide Web. The complete set of the CCD frames is available upon request.
3943. M2FS stellar spectroscopy of Reticulum 2
ID:
ivo://CDS.VizieR/J/ApJ/808/108
Title:
M2FS stellar spectroscopy of Reticulum 2
Short Name:
J/ApJ/808/108
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present results from spectroscopic observations with the Michigan/Magellan Fiber System (M2FS) of 182 stellar targets along the line of sight (LOS) to the newly discovered "ultrafaint" object Reticulum 2 (Ret 2). For 37 of these targets, the spectra are sufficient to provide simultaneous estimates of LOS velocity ({nu}i_los_, median random error {delta}_{nu}los_=1.4km/s), effective temperature (T_eff_, {delta}_Tef_=478K), surface gravity (logg, {delta}_logg_=0.63dex), and iron abundance ([Fe/H], {delta}_[Fe/H]_=0.47dex). We use these results to confirm 17 stars as members of Ret 2. From the member sample we estimate a velocity dispersion of {sigma}_{nu}los_=3.6_-0.7_^+1.0^km/s about a mean of <{nu}_los_>=64.3_1.2_^+1.2^km/s in the solar rest frame (~-90.9km/s in the Galactic rest frame), and a metallicity dispersion of {sigma}_[Fe/H]_=0.49_-0.14_^+0.19^dex about a mean of <[Fe/H]_>=-2.58_-0.33_^+0.34^. These estimates marginalize over possible velocity and metallicity gradients, which are consistent with zero. Our results place Ret 2 on chemodynamical scaling relations followed by the Milky Way's dwarf-galactic satellites. Under assumptions of dynamic equilibrium and negligible contamination from binary stars --both of which must be checked with deeper imaging and repeat spectroscopic observations-- the estimated velocity dispersion suggests a dynamical mass of M(R_h_)~5R_h_{sigma}_{nu}los_^2^/(2G)=2.4_-0.8_^+1.4^x10^5^M_{sun}_ enclosed within projected halflight radius R_h_~32pc, with mass-to-light ratio ~2M(R_h_)/L_V_=467_-168_^+286^ in solar units.
3944. M33 GALEX catalogue of UV point sources
ID:
ivo://CDS.VizieR/J/MNRAS/450/3811
Title:
M33 GALEX catalogue of UV point sources
Short Name:
J/MNRAS/450/3811
Date:
21 Oct 2021
Publisher:
CDS
Description:
The hottest stars (>10000K), and by extension typically the most massive ones, are those that will be prevalent in the ultraviolet (UV) portion of the electromagnetic spectrum, and we expect to numerous B, O and WR (WR) stars to be bright in UV data. In this paper, we update the previous point source UV catalogue of M33, created using the Ultraviolet Imaging Telescope (UIT), using data from the Galaxy Evolution Explorer (GALEX). We utilize point spread function photometry to optimally photometer sources in the crowded regions of the galaxy, and benefit from GALEX's increased sensitivity compared to UIT. We match our detections with data from the Local Group Galaxies Survey to create a catalogue with photometry spanning from the far-UV through the optical for a final list of 24738 sources. All of these sources have far-UV (FUV; 1516{AA}), near-UV (NUV; 2267{AA}) and V data, and a significant fraction also have U, B, R and I data as well. We also present an additional 3000 sources that have no matching optical counterpart. We compare all of our sources to a catalogue of known WR stars in M33 and find that we recover 114 of 206 stars with spatially-coincident UV point sources. Additionally, we highlight and investigate those sources with unique colours as well as a selection of other well-studied sources in M33.
3945. M giants in Cassiopeia
ID:
ivo://CDS.VizieR/J/PASJ/33/107
Title:
M giants in Cassiopeia
Short Name:
J/PASJ/33/107
Date:
21 Oct 2021
Publisher:
CDS
Description:
Coordinates and identifications for M-type stars in Cassiopeia
3946. M giants spectra and photometry
ID:
ivo://CDS.VizieR/J/A+AS/105/311
Title:
M giants spectra and photometry
Short Name:
J/A+AS/105/311
Date:
21 Oct 2021
Publisher:
CDS
Description:
From a sample of 97 very bright M-giant stars in the Solar neighbourhood, high-quality `intrinsic' spectra in the spectral range [380-900]nm for all M-spectral subclasses of the Case and MK classification systems are obtained. The results are fitted to photospheric synthetic spectra in the range [99-12500]nm in order to infer the corresponding continua. The synthetic spectra are also compared to the intrinsic spectra. The effective temperatures are derived and mathematical spectral classification criteria are found. The (UB)j(VRI)c(JHKLM)eso photometric data of the sample are also given.
3947. M-giant star candidates in LAMOST DR 1
ID:
ivo://CDS.VizieR/J/other/RAA/15.1154
Title:
M-giant star candidates in LAMOST DR 1
Short Name:
J/other/RAA/15.1
Date:
21 Oct 2021
Publisher:
CDS
Description:
We perform a discrimination procedure with the spectral index diagram of TiO_5_ and CaH_2_+CaH_3_ to separate M giants from M dwarfs. Using the M giant spectra identified from LAMOST DR1 with high signal-to-noise ratio, we have successfully assembled a set of M giant templates, which show more reliable spectral features. Combining with the M dwarf/subdwarf templates in Zhong et al. (2015AJ....150...42Z, Cat. J/AJ/150/42), we present an extended library of M-type templates which includes not only M dwarfs with a well-defined temperature and metallicity grid but also M giants with subtypes from M0 to M6. Then, the template-fitting algorithm is used to automatically identify and classify M giant stars from LAMOST DR1. The resulting catalog of M giant stars is cross-matched with 2MASS JHKs and WISE W1/W2 infrared photometry. In addition, we calculated the heliocentric radial velocity of all M giant stars by using the cross-correlation method with the template spectrum in a zero-velocity rest frame. Using the relationship between the absolute infrared magnitude MJ and our classified spectroscopic subtype, we derived the spectroscopic distance of M giants with uncertainties of about 40%. A catalog of 8639 M giants is provided. As an additional result of this analysis, we also present a catalog of 101690 M dwarfs/subdwarfs which are processed by our classification pipeline.
3948. M giant stars asteroseismology with Kepler and APOGEE
ID:
ivo://CDS.VizieR/J/AJ/160/18
Title:
M giant stars asteroseismology with Kepler and APOGEE
Short Name:
J/AJ/160/18
Date:
21 Oct 2021
Publisher:
CDS
Description:
Evolved stars near the tip of the red giant branch show solar-like oscillations with periods spanning hours to months and amplitudes ranging from ~1mmag to ~100mmag. The systematic detection of the resulting photometric variations with ground-based telescopes would enable the application of asteroseismology to a much larger and more distant sample of stars than is currently accessible with space-based telescopes such as Kepler or the ongoing Transiting Exoplanet Survey Satellite mission. We present an asteroseismic analysis of 493 M giants using data from two ground-based surveys: the Asteroid Terrestrial-impact Last Alert System (ATLAS) and the All-Sky Automated Survey for Supernovae (ASAS-SN). By comparing the extracted frequencies with constraints from Kepler, the Sloan Digital Sky Survey Apache Point Observatory Galaxy Evolution Experiment, and Gaia we demonstrate that ground-based transient surveys allow accurate distance measurements to oscillating M giants with a precision of ~15%. Using stellar population synthesis models we predict that ATLAS and ASAS-SN can provide asteroseismic distances to ~2x106 galactic M giants out to typical distances of 20-50kpc, vastly improving the reach of Gaia and providing critical constraints for Galactic archeology and galactic dynamics.
3949. M giant stars in the Sagittarius dwarf galaxy
ID:
ivo://CDS.VizieR/J/AJ/128/245
Title:
M giant stars in the Sagittarius dwarf galaxy
Short Name:
J/AJ/128/245
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have obtained moderate resolution (~6km/s) spectroscopy of several hundred M giant candidates selected from Two Micron All Sky Survey photometry (Cat. <II/246>). Radial velocities are presented for stars mainly in the southern Galactic hemisphere, and the primary targets have Galactic positions consistent with association to the tidal tail system of the Sagittarius (Sgr) dwarf galaxy.
3950. M87 globular cluster candidates catalog
ID:
ivo://CDS.VizieR/J/MNRAS/455/820
Title:
M87 globular cluster candidates catalog
Short Name:
J/MNRAS/455/820
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a new photometric catalogue of the rich globular cluster (GC) system around M87, the brightest cluster galaxy in Virgo. Using archival Next Generation Virgo Cluster Survey images in the ugriz bands, observed with Canada-France-Hawaii Telescope/MegaPrime, we perform a careful subtraction of the galaxy's halo light in order to detect objects at small galactocentric radii as well as in the wider field, and find 17620 GC candidates over a radius range from 1.3 to 445kpc with g<24mag. By inferring their colour, radial and magnitude distributions in a Bayesian way, we find that they are well described as a mixture of two GC populations and two distinct contaminant populations, but confirm earlier findings of radius-dependent colour gradients in both GC populations. This is consistent with a picture in which the more enriched GCs reside deeper in the galaxy's potential well, indicating a role for dissipative collapse in the formation of both the red and the blue GCs.